Efter att hon har vikt kläderna och ställt tvättkorgen i badrummet sätter hon sig i soffan och läser.

Efter att means after and introduces a clause.

• efter = after
• att = a conjunction here, linking the clause that follows

So Efter att hon har vikt kläderna ... means After she has folded the clothes ...

In English, we often just say after + clause. In Swedish, efter att is very common before a full clause with a subject and verb.

This is the perfect tense in Swedish.

• har vikt = has folded
• har ställt = has placed / put

The sentence describes two actions that are completed before the next action happens. First she folds the clothes and puts the laundry basket in the bathroom; after that, she sits down and reads.

So Swedish uses:

• har
  • supine
• vika → vikt
• ställa → ställt

This is similar to English has folded and has placed.

Because both verbs share the same auxiliary verb har.

So:

• hon har vikt kläderna och ställt tvättkorgen ...

means:

• she has folded the clothes and placed the laundry basket ...

Swedish often avoids repeating the auxiliary when it applies to both verbs. English does the same:

• She has folded the clothes and placed the basket.

Not:

• She has folded the clothes and has placed the basket.

Both are possible, but the repeated auxiliary is usually unnecessary.

Because vika is an irregular verb.

Its main forms are:

• infinitive: vika
• past tense: vek
• supine: vikt

So in the perfect tense you say:

• har vikt

not har vikat

This is something you simply have to learn with the verb.

This is because Swedish follows the V2 rule in main clauses: the finite verb normally comes in the second position.

The sentence begins with a long introductory clause:

• Efter att hon har vikt kläderna och ställt tvättkorgen i badrummet

After that comes the main clause, and the finite verb must come second:

• sätter = second element
• hon = comes after the verb

So:

• Efter att ..., sätter hon sig ...

This is very common in Swedish. Compare:

• Hon sätter sig i soffan.
• Efter att hon har vikt kläderna, sätter hon sig i soffan.

In English, we keep she sits down, but Swedish inverts the order after an introductory element.

Sig is a reflexive pronoun, like herself in English, although English often leaves it out.

The verb is sätta sig, which means to sit down.

So:

• sätta = to set / put
• sätta sig = to sit down, literally set oneself

That is why sig is needed here.

Compare:

• Hon sätter boken på bordet. = She puts the book on the table.
• Hon sätter sig i soffan. = She sits down on/in the sofa.

Without sig, the meaning would change completely.

They are related, but not the same.

• sätter sig = sits down; it describes the movement/change into a sitting position
• sitter = is sitting; it describes the state

So here:

• sätter hon sig i soffan och läser
  = she sits down on the sofa and reads

If you said:

• hon sitter i soffan och läser

that would mean:

• she is sitting on the sofa and reading

So sätter sig focuses on the action of taking a seat.

Swedish often uses i where English uses on, especially with things you sit down into, such as sofas and armchairs.

So:

• i soffan = literally in the sofa, but naturally translated as on the sofa

This is just one of those places where Swedish and English use different prepositions.

You may also hear på soffan in some contexts, but i soffan is very common and natural when the idea is sitting down into the sofa.

Swedish often uses the definite form when talking about specific, identifiable things in the situation.

Here:

• kläderna = the clothes
• tvättkorgen = the laundry basket
• badrummet = the bathroom
• soffan = the sofa

In Swedish, definiteness is usually shown by an ending on the noun:

• kläder → kläderna
• tvättkorg → tvättkorgen
• badrum → badrummet
• soffa → soffan

English uses a separate word, the, while Swedish usually attaches the definiteness to the noun itself.

In Swedish, just like in English, the object can be left out if it is not important or is understood generally.

So:

• läser = reads / is reading

Here it simply means that she sits down and reads, without specifying what she is reading.

English does the same:

• She sat down on the sofa and read.

You do not always need to say a book, the newspaper, and so on.

Because the sentence is describing a sequence of actions from the perspective of a present-time narration.

• har vikt, ställt = actions completed before the next action
• sätter, läser = the main actions being described now in the narrative

This kind of tense combination is normal. The perfect shows earlier completed actions, and the present shows what happens next.

If the whole sentence were told in the past, it would usually become something like:

• Efter att hon hade vikt kläderna och ställt tvättkorgen i badrummet satte hon sig i soffan och läste.

So the pattern stays the same, but all the tenses shift back.

Yes, a comma is possible there, but modern Swedish often leaves it out unless it helps readability.

So both of these can be seen:

• Efter att hon har vikt kläderna och ställt tvättkorgen i badrummet sätter hon sig i soffan och läser.
• Efter att hon har vikt kläderna och ställt tvättkorgen i badrummet, sätter hon sig i soffan och läser.

In many modern texts, the version without the comma is more typical. The important thing for a learner is not the comma, but the word order after the introductory clause: sätter hon sig, not hon sätter sig.